Objectives: The present study compared the interval until device exchange or death from pump-related failure in patients with pulsatile versus continuous flow left ventricular assist devices. Methods: Data from Interagency Registry for Mechanically Assisted Circulatory Support (June 23, 2006, to March 31, 2011) compared the durability of implanted pulsatile and continuous flow left ventricular assist devices. The durability issues included pump replacement for infection, thrombosis-hemolysis, driveline failure, or pump drive unit failure, and death from driveline or pump drive unit failure. Results: A total of 3302 left ventricular assist devices were implanted (486 pulsatile, 2816 continuous flow) and 98 pump exchanges or deaths from durability issues (46 pulsatile, 52 continuous flow; 3% of implants). The interval to device issue was greater for the continuous flow than for the pulsatile devices (P <.001). A comparisons of the causes for pump exchange or pump-related death showed (1) greater freedom from pump failure in the continuous flow compared with the pulsatile left ventricular assist devices (10 events/2816 continuous flow implants vs 39 events/486 pulsatile implants; P <.0001); (2) similar exchange or pump-related death for driveline failure (1/486 pulsatile vs 7/2816 continuous flow; P =.82); (3) similar exchange or pump-related death for thrombosis-hemolysis (2/486 pulsatile vs 28/2816 continuous flow; P =.25); and (4) fewer exchanges or pump-related deaths from infection in continuous flow left ventricular assist devices (4/486 pulsatile vs 7/2816 continuous flow; P =.034). Competing outcomes analysis corroborated this finding, with 54% of continuous flow versus 23% of pulsatile patients alive and receiving support at 12 months after implantation. Conclusions: The Analysis of Interagency Registry for Mechanically Assisted Circulatory Support data showed greater durability for continuous flow than for pulsatile left ventricular assist devices. Even longer durations of support can be expected if pump durability continues to improve. © 2013 by The American Association for Thoracic Surgery.